Artificial hand and arm.



L. G. CARON.

ARTIFICIAL HANDAND ARM.

APPLICATION HLED DEC- 15. I917.

Patented July 9, 191

2 SHEETS-SHEET L. G. CARON.

ARTIFICIAL HAND AND ARM.

APPLICATION FILED DEC 1:. i911.

rial/14??? Patented July 9, 191-8. 2 sHEETs-sman 2 JNVENZ'UH.

LOUIS GABON, OF TORONTO, ONTARIO, CANADA.

ARTIFICIAL HAND AND ARM.

Specification of Letters Patent.

Patented July 9, 1918.

Application filed December 15, 1917. Serial No. 207,335.

T 0 all whom it may concern:

Be it known that I, LoUIs G. CARoN, a citizen of United States of America, residing in the city of Toronto, county of York, Province of Ontario, Canada, have invented certain new and useful Improvements in Artificial Hands and Arms, of which the following is a specification.

This invention relates to artificial members for use in cases where the natural arm has been removed either above or below the elbow. A principal object of my invention is to provide a hand of normal appearance, which, when desired, may be used in much the same way and as effectively as the hook hands now on the market.

Further objects are to provide means for readily disconnecting the hand from the arm, to provide for various wrist movements to enable the hand to assume various positions approximating those possible with the natural hand, and to provide effective means for bending the forearm member on the upper arm member when the arm is constructed for above-the-elbow amputations.

I attain my objects by means of the constructions hereinafter described and illustrated in the accompanying drawings in which- Figure l is a side elevation of a hand and part of the forearm member constructed in accordance with my invention, parts being shown insection 5 Fig. 2 is a simllar view of the upper arm member and forearm member complete, being complementary to Fig. 1;

Fig. 3 a longitudinal section of the hand illustrating more particularly the hook which cooperates with the thumb and fingers;

Fig. 4 a front elevation of the hand;

Fig. 5 a section on the line gh in Fig. 3, showing more particularly the slots of the ball member of the wrist joint;

Fig. 6 a front elevation. partly broken away, of the upper arm and forearm members' Fig. 7 a section on the line ab in 2;

Fig. 8 a section on the line 0Z in Fig. 2; and

Fig. 9 a section on the line ef in Fig. 2.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

Referring particularly to Figs. 2 and 6, 1 1s an upper arm socket member adapted to fit on the stump of the upper arm, and 2 is aforearm member hinged thereto, the hinge pm 3 preferably extending from side to side of the joint. On this hinge pin is secured the curved guide 4. Over this guide passes the cord 5, which passes out through a hole in the back of the upper arm member.

A small guide sheave 6 is preferably provided to reduce the friction and give the cord a proper lead. The upper end of this cord will be connected with any suitable harness as is common in artificial members of the same general type. The other end of the cord, after passing around the guide, is secured to an arm 7 pivoted at 8 on the forearm member and extending through a short slot 9 formed therein, so that the arm has a limited movement longitudinally of the forearm member. By a pull on the cord 5, the forearm member may thus be swung on the hinge pin 3. 1

To lock the forearm member against the extension after being flexed, I provide an arc-shaped rack 10 concentric with the hinge pin 3 and preferably formed on the curved guide 4. With this rack there engages a dog 11 preferably rigidly connected with the operating arm 7, so that when the arm is drawn up by the cord, the first movement of the arm disengages the dog. The spring 12, engaging the dog and the forearm member, tends to yieldingly maintain the dog in engagement with the rack.

From this construction it is evident that as long as a slight pull is maintained on the cord the dog will be held out of engagement with the rack and the arm thus left free to swing in either direction. The instant, however, tension on the cord is released, the dog will engage the rack and hold the forearm member bent on the upper arm member to the desired extent.

To the end of the forearm member is detachably connected the wrist member 13, the connections being such that the wristmember will rotate on an axis longitudinal of the forearm member. The forearm member is finished with a flat end plate 14 to which is connected a sleeve 15 extending .into th forearm member and adapted to it does not rotate relative thereto.

of the wrist member 13. The stem may be held in any desired position of rotary adjustment by means of the set screw 19 passing through the forearm member and threaded through the side of the sleeve 15.

and engages in an annular groove 24 formed in the stem 17.

It is desirable that the hand should occupy substantially the position shown in Fig. 1 when the arm is extended as shown in Fig. 2, and that it should be automatically turned at the wrist when the forearm is bent on the upper arm. To eifect this movement I provide the following mechanism.

At one end of the joint between the forearm and upper arm, andconcentric with the hinge pin 3, I provid a pulley 16, which is so secured to the upper arm member that Around this pulley is passed a cable 25. This cable is also secured to the pulley so that it does not move relative thereto, as, for example. by pinning or stapling it thereto.

The parts of the cable are led through suitable holes into the interior of the forearm and are connected to the arms of a T-lever 26 fulcrumed adjacent the outer end of the forearm member, preferably in a manner hereinafter described. The stem of the T-lever is engaged with the plate 18 so as to turn the wrist member when rocked in its fulcrum. Preferably I cut out the plate 18 to form a bar 27 with a space at either side thereof, and shape the stem of the T-lever as a fork 28 embracing this bar, (see Fig. 7).

To guide the stem I form a slot 29 in the plate 14 as shown particularly in Fig. 8.

It is not always desirable to have the wrist turn automatically when the forearm is swung up on its joint. I therefore provide means whereby the stem of the T-lever may be withdrawn from engagement with the bar 27 when desired. I show for this purpose the fulcrum 30 of the T-lever formed with a stem 31 of less diameter projecting through a slot 32 formed in the wall of the forearm member. Two enlargements 33 are formed in this slot adapted to receive the fulcrum 30. By pushing in the stem 31, the fulcrum may be disengaged from one and moved up or down as the case may be for engagement with the other. WVhen the fulcrum is in the upper enlargement the T-lever is in operative position. When the fulcrum is in the lower enlargement the plat 14 is freed from engagemeiu. with the stem of the T-lever and the flexing of the forearm on its joint no longer effects a movement of the Wrist member. A bent spring 34 secured withinthe forearm member tends to retain the fulcrum 30 in either of the enlargements with which it may be engaged.

The hand is connected with the wrist member by means of a ball and socket joint providing means whereby the hand may be hinged on the wrist member in either of tWo planes. The wrist portion of the hand is formed as a hollow ball member 35 adapted to fit the cup 36 formed on the outer end of the wrist member. The ball is provided with a plurality of intersecting slots 16. A headed bolt 37 is screwed into the wristmember, its end preferably extending down into the stem 17. The head of this bolt engages the inner surface of the hollow ball, while its stem is adapted to pass through either of the slots. To prevent slipping, the slots are preferably cupped as shown at 38 in several different positions, and the head of the bolt suitably shaped to enter these cupped depressions. It is evident that when the bolt is screwedup tight with its head engaging anyone of the depressions, the hand will be rigidlyheld in a certain position. As shown, five. different positions are possible, the hand being either swung forwardly, backwardly, to the right or the left. or held in a normal central position such as shown in Fig. 1.

The screw is tightened or loosened by means of a pin 39 connected with the stem of the bolt and extending out through a slot 40 formed in the wrist member.

The construction of th hand is novel in many particulars, one of the essential features being an arrangement whereby not only do the thumb and fingers. work in opposition to grasp any object, but thereis also provided a hook member at the opposite sid of the palm of the hand to the thumb also adapted to work in opposition to the fingers.

In the preferable arrangement both the hook and the thumb swing in opposition to the finger or fingers while the latter may be either stationary or movable to enable the hand to be used in grasping objects of large diameter. The thumb 41 is pivoted. at 42 to swing on an aXis transverse of the palm of the hand. Its inner end is provided with a ratchet rack 43, which is engaged b v a spring actuated dog 44 suitably fulcrunied within the hand and having an operating arm 45 extending out through a suitable opening or slot in the hand. The coil spring 46 is located on th pivot pin of the thumb and is provided with arms, one of which engages a pin 71 on the ratchet rack 43 of the thumb and the other a suitable stationary part 47.

This spring tends to move the thumb away from the fingers. The fingers are preferably rigidly connected to a knuckle member 48. This knuckle member may be fixedly secured to the hand, but is preferably pivoted on the hinge pin 49, extending transversely of the hand.

A rack 50 is formed on the knuckle member, which is engageable by the latch 51 pivoted at 52 within the hand and projecting at the opposite side of the hand through a slot 53. A spring 54 tends to hold the latch in engagement with the rack. A' spring 55 coiled on the hinge pin 49 is provided with an arm engaging the knuckle member and another arm engaging the stationary part 56. This spring tends to swing the fingers toward the thumb. This action, however, can only take place when the latch 51 is disengaged from the rack 50.

To hold this latch disengaged I form at one end of the slot 53 the hook-shaped enlargement 57 into which the end of the latch 51 may be pressed and hooked to hold it out of engagement with the rack. The fingers may then be automatically extended in the manner now common in the art, a cord 58 being provided for that purpose, which passes through a hole in the back of the hand and is connected at its outer end with one of the fingers or the knuckle connecting them as shown. This cord 58 is connected by means of a detachable hook 59 with a cord 60, which may be connected with any suitable operating harness on the wearers body such as is now common in the art.

At the opposite side of the palm of the hand to the thumb I pivot the hook 61, which hook works through a slot formed in the palm of the hand so that it may be either swung up to the position shown in dotted lines in Fig. 3, or, when not required, swung down out of the way as shown in full lines. This hook is provided with a ratchet rack 62 concentric with its pivot or hinge pin 63, and with this rack engages the spring actuated dog 64, which dog has an arm 65 extending out through a hole or slot in the hand, and by means of which it may be disengaged from the rack when necessary.

Each finger has preferably a cushion 66 of rubber or other suitable elastic or semielastic material inserted in its inner surface. These rubber cushions materially increase the security of the grip of the fingers on any object grasped between them and the thumb and hook.

For some purposes it is desirable that the ends of the forefinger and thumb should cooperate in graspin r an object, while, when an object is to fie grasped between the fingers and the thumb and hook, it may be necessary for the end of the thumb to pass the forefinger.

I therefore hinge the end 67 of the thumb.

at 68 on the main part of the thumb. Coacting shoulders 69 are formed on the parts of the thumb, which prevent the end swinging in too far across the palm of the hand. The coil spring 7 0 is located on the hinge pin 68 and is provided with one arm en aging the thumb end and another arm suita 1y engaging the main part of the thumb. This coil spring tends to move the thumb end to its forefinger end engaging position. It is, however, easily swung outwardly by the users other hand when an object is to be grasped between the fingers and the thumb and hook.

When an object, as, for example, the

' handle of a tool, is to be grasped, it 1s placed within the curve of the fingers and the thumb by means of the other hand, pressed securely into engagement with it. The hook 61 is also swung up to engage it in opposition to the fingers. The object is then securely grasped between the thumb and hook and one or more of the fingers as the case may be, depending on the exact shape of the article being grasped. Owing to the resilient cushions inside the fingers a close tight grip is obtained on the object, which enables the wearer to effectively handle his tool, the grip being as efiicient as in the hook type of hands commonly employed, while the appearance is that of the ordinary artificial hand made in imitation of the natural hand.

Ordinarily the fingers will not require to be jointed. For very large objects it may be necessary to adjust the fingers on the hinge pin 49 as hereinbefore described.

\Vhat I claim as my invention is 1. In an artificial hand, the combination with a finger and a thumb, one being pi"- oted so that it may be swung toward the other, of a hook extending in substantially the same direction as the finger and thumb and pivoted at the opposite side of the palm from the thumb to swing in opposition to the finger. I

2. In an artificial hand, the combination with a grasping member comprising a plurality of curved fingers in fixed relationship to one another, and a grasping member formed as a thumb, one member being pivoted so that it may be swung toward the other, of a hook extending in substantially the same direction as the finger and thumb and pivoted at the opposite side of the palm from the thumb to swing in opposition to the fingers.

3. In an artificial hand, the combination with a finger and a thumb, one being pivoted so that it may be swung toward the other, of a hook extending in substantially the same direction as the finger and thumb and pivoted at the opposite side of the palm from the thumb to swing in opposition to the finger, a recess being formed in the hand adapted to substantially receive said hook;

and releasable means for holding the hook projected in engagement with any object grasped between the thumb and finger.

4. In an artificial hand, the combination of a finger; a thumb pivoted to swing in opposition to the finger; a hook extending in substantially the same direction as the finger and thumb and pivoted at the opposite side of the palm to swing in opposition to the fin er; and releasable means for holding both the thumb and hook in engagement with any object engaged at its other side by the finger.

5. In an artificial hand, the combination with a grasping mem'ber comprising a plurality of curved fingers in fixed relationship to one another and having their inner sides provided with rubber cushions, and a graspmg member formed as a thumb, one member being pivoted so that it may be swung toward the other, of a hook extending in substantially the same direction as the finger and thumb and pivoted at the opposite side of the palm from the thumb to swing in opposition to the fingers.

6. The combination of a wrist member having a cupped socket formed at its outer end; a hand member having a hollow ball formed thereon adapted to engage the socket, said ball having intersecting slots formed therein; a headed bolt screwed into the wrist member having its head adapted to engage the inner surface of the hollow ball while its stem passes through a slot; and a pin connected to the stem of the bolt and extending laterally, the wrist member being slotted for its passage.

7. The combination of a wrist member having a stem projecting therefrom having an annular groove formed in its periphery; a forearm member having a longitudinal hole formed in its end; a metal sleeve lining the hole into which the stem is adapted to fit, the sleeve having a slot at one side in alinement with the aforesaid groove; and a releasable catch carried by the forearm member engaging said groove through the said slot.

8. The combination of a wrist member having a stem projecting therefrom having an annular groove formed in its periphery; a forearm member having a longitudinal hole formed in its end; a metal sleeve lining the hole into which the stem is adapted to fit, the sleeve having a slot at one side in alinement with the aforesaid groove; a releasable catch carried by the forearm member engaging said groove through the said slot; and a set screw passing through the forearm member and sleeve adapted to clam the said stem in the sleeve.

9. *lhe'combination of a forearm member; a wrist member journaled thereon on an axis longitudinal of the forearm member; a T- lever fulcrumed on the forearm member having its stem engaged with the wrist member to turn the same; an upper arm member hinged to the forearm member; cable operating means connected to the upper arm member adjacent the hinge pin; a cable secured to said cable operating means and haviiw'its ends connected to the arms of the T- lever.

10. The combination of a forearm member; a wrist member journaled thereon on an axis longitudinal of the forearm member; a T-lever fulcrumed on the forearm member having its stem engaged with the wrist member to turn the same; a plate secured to the forearm member provided with a guide slot through which the arm of the lever passes; an upper arm member hinged to the forearm member; cable operating means connected to the upper arm member adjacent the hinge pin; a cable secured to said cable operating means and having its ends connected to the arms of the T-lever.

11. The combination of a forearm member; a wrist member journaled thereon on an axis longitudinal of the forearm'member; a T-lever having its stem engaged with the wrist member to turn the same; a fulcrum for the T-lever adjustable on the forearm member so that the stem of the lever may be engaged with or disengaged from the wrist member; an upper arm member hinged to the forearm member; cable operating means connected to the upper arm member adjacent the hinge pin; a cable secured to said cable operating means and having its ends connected to the arms of the T-lever.

12. The combination of an upper arm member; a hollow forearm member hinged thereto; an operating cord led through the upper arm member; a guide in front of the hinge joint over which the cord passes; an arc-shaped rack rigid with the upper arm member and concentric with the hinge pin; a spring actuated dog on the forearm member normally tending to engage the rack; and a member having a limited movement longitudinally of the arm to which the cord is attached, said member being operatively connected with the dog.

13. The combination of an upper arm member; a hollow forearm member hinged thereto; an operating cord led through the upper arm member; a guide in front of the hinge joint over which the cord passes; an arc-shaped rack rigid with the upper arm member and concentric with the hinge pin; a bent lever fulcrumed within the arm at the back thereof, one end being formed as a dog to engage the rack and the other extended through the front of the forearm member and forming an operating arm to which the cord is attached, the opening for the said arm in the forearm member being elongated to permit of a limited movement of the said arm longitudinally of the forearm member; and a spring normally tending to engage the dog with the rack.

14. In an artificial hand, the combination of a finger; a thumb pivoted to swing in opposition to the finger and jointed to permit of the ti swinging in a direction transversely 0 the hand; a spring tending to move the thumb away from the fingers; and pawl and ratchet rack mechanism for holdmg the thumb.

15. In an artificial hand, the combination of a finger; a thumb pivoted to swing in opposition to the finger and jointed to permit of the tip swinging in a direction transversely of the hand; a spring tending to move the thumb away from the fingers; v

of Sept 1917, in the presence of the two undersigned witnesses.

LOUIS G. GABON.

Witnesses:

J. Enw. MAYBEE, GEO. P. MAOKIE. 

